Pellet mill



E. T. MEAKIN PELLET MILL July 26, 1938.

Filed Jan. 5, 1934 3 Sheets-Sheet 3 INVEN TOR, 506/72 7. WEAK/N wada ig ATTORNEY Patented July 26, 1938 UNITED STATES PATENT OFFICE 1 20 Claims.

My invention relates to pellet mills, and more particularly to extrusion devices whereby moldable materials may be forced through a die plate, and cut off as they emerge, to form pellets. The

device is particularly adapted for the formation of pellets from feed meal and similar materials. Certain of the structure herein shown has already been described and claimed in my copending application, Serial No. 574,944, filed November 14, 1931, issued April 10, 1934 as Patent N0.

1,954,086, for a Pellet mill".

The principal object of my invention is to provide improved means for forming pellets from moldable materials.

Other objects of my invention are: to provide a vertical extrusion press wherein materials may be rolled through an apertured die plate and thereafter cut off to form pellets; to provide such a structure wherein cut-oif knives may be rotated around the die plate at a rate of speed difiering from that of the roller shaft; to provide a pellet mill wherein cut-off knives are operated independently of the shaft driving the extrusion means; to provide a pellet mill of the character described, having an improved cut-off knife drive; to provide means for easily removing the die block in a vertical pellet mill; to provide means for quickly removing and changing cut-off knives in a vertical pellet mill; to provide improved means for handling thrust stresses in a vertical extrusion press; to provide a means for relieving an extrusion press frame of thrust stresses; and to provide a pellet mill of simple construction.

Other objects of my invention will be apparent or will be specifically pointed out in the description forming a part of this specification, but I do not limit myself to the embodiment of the invention herein described, as various forms may be adopted within the scope of the claims.

Referring to the drawings:

Figure 1 is a longitudinal sectional view of one embodiment of my invention wherein the die block is fastened to a roller supporting stud.

Figure 2 is a plan view of the knife driving gears.

Figure 3 is a plan view, looking from the bottom of the mill shown in Figure 1.

Figure 4 is a longitudinal view of another embodiment of my invention, wherein the die plate is supported solely by its periphery.

Figure 5 is a plan view, looking down on the mill of Figure 4.

In broad terms, my invention comprises an apertured die block and means for forcing material through the die block, said means preferably comprising rollers operating on the top surface of the die block. Cut-off knives are mounted below the die block and are operated, preferably from an external shaft, through suitable gearing, or similar power transmitting means, whereby 5 the knives may be rotated at a difierent rate of speed than the rollers, In certain instances I may prefer to lock the center of the die block to the frame through the medium of a thrust stud, and relieve the frame of thrust stresses, and in 10 other embodiments I may desire to leave the center of the die block entirely unsupported, stress being transmitted to the frame through the periphery of the die block. In either case, I prefer to mount the cut-off knives on a ring gear held in 15 a split ring, or similar device, which also serves to maintain the die block in position. Removal of this split ring therefore allows a quick removal of either the knives or the die block, or both, as desired. 20

My invention may be more fully understood by detailed reference to the figures, attention being directed first to the embodiment shown in Figure 1. Here a press frame I, preferably of cast'construction, is provided at its upper end with a top 25 plate 2, carrying an axial positioning bearing 4. Mounted and adapted to rotate in this bearing is a thrust adjustment nut 5 having interior threads 6. Screwed into the threads is a strong thrust stud 1, extending axially through the 30 frame. The lower end of the thrust stud l is provided with internal threads 9 which receive a threaded portion IU of a die block nut II. This die block nut is provided with a channel l2 in which is inserted a removable split ring shoulder 35 M. The lower end of the frame is provided with a die plate shoulder I5, machined to receive the periphery of a circular die plate 16, provided with extrusion apertures l1 and a central aperture I9, into which the main body of the die block nut is received, the split ring l4 acting as a shoulder, bearing against the lower face of the die plate. screwing the threaded portion ll] of the die block nut intothe end of the thrust stud 1 will force the die plate against the shoulder 15 and hold the die plate solidly in place against the frame.

A drive sleeve 20 surrounds the thrust stud I, being provided at its extreme upper end with a thrust bearing 2|, backed by a thrust collar 22, which in turn bears against the thrust adjusting nut 5. The lower end of the drive sleeve is expanded to form a roller frame 22', which in turn carries roller bearing studs 23 upon which extrusion rollers 24 are mounted through the medium of roller bearings 25. I prefer to set the rollers so that they will revolve closely adjacent the top surface of the die plate. The drive sleeve is further positioned by a horizontal sleeve web 20, and is driven through a large gear 21 attached to the drive sleeve, and a small gear 29 attached to a power shaft 30. I prefer to mount the power shaft on the frame by means of ball bearings ll and 22, and apply power to the shaft through a pulley 34.

It will be observed that the thrust bearing 2| and its associated thrust structure is enclosed in a chamber formed in the upper end of the press frame I between the plate 2 and the web 26. Thus positioned, the thrust structure is protected from wear and breakage caused by the entrance of dust and other destructive foreign matter which is ever present in the handling of moldable materials such as meals, meshes and the like.

The power shaft is preferably provided with an extension 35 outside of the frame which terminates at a point adjacent the plane of the lower surface of the die block, and is there provided with a bearing 38 and a knife driving gear 31. The knife driving gear 31 meshes with a floating ring gear 39, which is held in position by a split ring 40. Bolts 4|, engaging lips 42, clamp the split ring around the frame and thus position the ring gear with respect to the die plate. I also prefer to provide a shoulder 44 on the split ring which engages the lower surface of the die block at its periphery. The ring gear is then used to support a pair of knives 45 which are in contact with the lower surface of the die plate below the extrusion apertures.

The frame I is preferably extended to form a pellet receptacle and standard 46 below the die plate. I also prefer to provide the frame I with an inlet chute 41 through which material may be fed in to the rollers and, by them, forced through the die apertures.

In this particular embodiment it will be seenv that the thrust path is as follows: beginning with the rollers 24, through the ball bearings 25 to the roller bearing stud 23, through the drive sleeve 20 and the thrust bearing 2I to the thrust block 22, thence to the thrust adjusting nut, into the thrust stud 1, back down to the die block nut I I, and thence back to the die plate itself through the ring l4. None of the thrust is taken on the frame itself, the frame merely serving to position and maintain the thrust stud and drive sleeve in their correct axial and central position.

The embodiment shown in Figure 4 differs from that shown in Figure 1 mainly in that the thrust in this case is transferred directly to the frame, there being no thrust stud present. In this case the upper plate 2 is provided with a thrust adjustment nut 5 which bears directly on the drive sleeve 20 through the thrust bearing 2|. The rollers 24 are supported in the frame in the same manner as in the previously described machine, and power is applied to the sleeve in the same manner. The knives are also driven through knife gears, as described above. The die block in this case, however, is not centrally apertured, as it is not required to receive the end of a thrust stud. In this case it will be obvious that the thrust is taken from the rollers through the sleeve and its thrust bearing 2| and passed into the top plate 2, and thence to the frame, the thrust on the die block being passed into the frame through the split ring 40.

There are no rotational parts passing through the die block in either machine, and the knives may be made to rotate at any speed desired by the proper selection of knife gears. The main features of the two devices, therefore, are essentially the same, the only difference being the method of handling the thrust.

I have found that the presses, as described, having knives rotating at a different number of revolutions per minute than the drive sleeve, have numerous advantages over those previously described. The acceasibility to the die block and knives is greatly enhanced, and pellets of different length may be readily obtained without disturbing the extrusion portion of the mill. I find that I can obtain more precise regulation of the length of pellets by regulating the rotational speed of the knives. I also find that I am able to greatly simplify die plate construction, and thus cheapen the manufacture of the device, without sacrificing any of the advantages of previous machines. It should also be noted that by driving the knives from the periphery of the die plate, all obstruction to the delivery of material has been removed from the delivery path thus greatly facilitating passage of material such as dough, or similar sticky substances. The entire set-up makes for simplicity of operation and maintenance, as well as giving the machines an adaptability for wider uses and varied products.

I claim:

1. In apparatus adapted to extrude material through an apertured die plate, means for cutting off said material mounted beneath said die plate comprising an annular bearing attached to said die plate surrounding the apertures therein and opening inwardly, a ring floating in said bearing, a knife attached to said ring and extending inwardly across said apertures, and means for rotating said ring.

2. In apparatus adapted to extrude material through an apertured die plate, means for cutting off said material comprising an annular bearing attached to said die plate surrounding the apertures therein and opening inwardly, a ring floating in said bearing, a knife attached to said ring and extending inwardly across said apertures, and means for rotating said ring, said bearing being segmentally separable to allow removal of said ring.

3. In apparatus of the class described, a housing, an apertured die plate removably disposed in said housing, a plurality of rollers disposed ad- 'acent one face of said die plate in rotatable relationship therewith for compressing and forcing material through said apertures, a knife mounted adjacent the other face of said die plate for movement over said face in a direction transverse to the axes of said'apertures, a member secured to said knife, means for rotating said rollers, means for rotating said member to move said knife, and common means for securing said die plate and said member to said housing.

4. In apparatus of the class described, a housing, an apertured die plate removably disposed in said housing, a plurality of rollers disposed adjacent one face of said die plate in rotatable relationship therewith for compressing and forcing material through said apertures, a knife mounted adjacent the other face of said die plate for movement over said face in a direction transverse to the axes of said apertures, a ring secured to said knife and surrounding said apertures, means for rotating said rollers and said ring to move said knife, and means engaging both said die plate and said ring for securing said die plate and ring to said housing. 1

5. In apparatus of the class described, a housing, an apertured die plate removably disposed in said housing, a plurality of rollers disposed adjacent one face of said die plate in rotatable relationship therewith for compressing and forcing material through said apertures, a knife mounted adjacent the other face of said die plate for movement over said face in a direction transverse to the axes of said apertures, a ring secured to said knife and surrounding said apertures, means for rotating said rollers and 'said ring to move said knife, an arcuate member engaging said ring and said die plate for securing said ring and plate to said housing in spaced parallel relationship, and means for rotating said rollers and said ring to move said knife. Y 6. In apparatus of the class described, a housing, an apertured die plate removably disposed in said housing, a plurality of rollers disposed adjacent one face of said die plate in rotatable relationship therewith for compressing and forcing material through said apertures, a knife mounted adjacent the other face of said 7 die plate for movement over said face in fadirection transverse to the axes of said apertures, an arcuate member securing said die plate to said housing, said member having an arcuate groove therein, a ring slidably mounted in said groove and secured to said knife, means for'rotatingsaid rollers, and means for moving said ring in said face of said die through said apertures, "as'plit ring having a portion thereof securing said ,die plate and housing togethergnd aportio'njprovided with a peripheral groove,,'anannular member mounted in said groove Iinlrotatabie'relatioriship with said die, a knifejsecured said'rneniher and projecting oveataeiower surfacejof "said die, and means projecting intosaid'groove 1nd engaging said membenforrotatingesaid me her and moving said knifelover' paegar'z e o'f 'said,

die plate in a planel transverse withthela'xes f said apertures.

8. In apparatus of e class described a housing, an apertured, 'diepiate removably disposed in said housing, a supported in saidlious'ing adjacent said die:plate,;1a, roller-mounted on said shaft and disposed tangent, ripheral. relationship with the ,apertured surface of saidj die.

means for rotating,saidlshaft and saidiroller jto compress and force, material deposited on the surface of said die through ,said, apertures, a split to rotate parallel and co-axially therewith, 'a'knife carried by said ring "gear and movable therewith 1 for severingat ,thefsurface of the die plate the material asfit is 'fextruded'" therethrough said knife being" the, onlyfelement overlying the surface of'said dieplate mans,:'for rotating said ro-f tating member,"and meansoutside the "discharge.

p'atli of the material for rotating s'aidrin'g' gear. 10, In apparatus of the class described, a hous ing, an upright member'adapted to herotated' mounted in 'saidihousing, a. hbrizontallyjposb tioned apertured di'ej plate, 'means for support-" ing' said die plate, .so constructed and arranged as not to, overlie the apertured portion of said die plate, apluraiity offrollers mounted on said upright member adapted to compressand ,force' V material through said die plate, a ring gear positioned substantially at the surface'of the die plate to rotate parallel and co-axially therewith, 'a'

knife carried by said ring gear and movable therewith'for severing at the surface of the die plate thematerial as it is extruded therethrough meansffor rotating'said rotating member, and

means connected with the periphery of said'ring gear for drivingthesame, p g 11.: In'apparatus of theclas sdescribe'd, a housl, ing' an upright memberadap'ted'to" be rotated mounted in'said housing; a thrustbearing mount edon and adjacent the top of the housing and in which the'uppenehd of the rotatingfmember is journale'd, mean's forfsupporting the rotating member inupright position, a horizontally posi-f tioned l'diefhaving extrusion apertures] therein,

means for supporting saidifdie on said housing,

Miami b ol er m un ed or m v me t" t aid bt ti a m e an pted to[ e re and force materialthrougljrsaidapertures; a knife o tio e ow said d e or movem t abo nd in contactfwith' the face; thereof, means for ,rqtating said ri t name beri d 'inean ou e;

of"thedeliver y path 'adjacentfthe{periphery or.

said die'for rotatingl iildiknife tof cutoffthe ude ma eri aid, eei v yf at below Sai knife beingjinohstructedflf J; 'ap at dn s throughf an' 'apertured "d plate, means for cut v ting Off said material comprising a', floating ring? H355 1 a the afi u n*. a d Plate an subs; stantially'in the planeof-the surface thereof; a; knifelatta to, said ring gear and extending inwardly across said .apeijturea saidknife.being,

gear atta h d":to g a a,plat and positioned to.

the only .elment, vin the delivery path of the extruded imaterial' andvmeans connected with the p n ts: am edemaar meviw-safiqailei throughits orbital path.;

of sa i'd die platefor compressing meaning I rotated. mounted injsaidhousingJ-a horizontally positioned', apertured die plate, nieansfor supporting said die a plate, plurality of mne'r s mou tedc said iupiright'flmemb'er adapted toflcompress and 'folrcematerial .throughsaid are plate, a ring gear 'posi i tionedsubstantially at the surface of the die plate efmateiialj E ,14. ,In apparatus of the class descrlbeda per-11' ted die plate, a column centrally supporting, I 1 elar l ef ffhiqu e f o ita fi qra:

g m h i a d c mi l' daadi nt ne fa appaiatusbr the class described, hulls material through said perforations, and means independent of said column for moving said roller through its orbital path.

15. In apparatus of the class described, a perforated die plate, a stationary column supporting said die plate, a rotatable sleeve surrounding said column, a roller depending from said sleeve and adjacent one face of the die plate for compressing and forcing material through said perforations, and means for rotating said sleeve and roller about the column axis.

16. In apparatus of the class described, a perforated die plate, a stationary shaft secured to said die plate, a sleeve disposed about said shaft, means mounted on said sleeve for movement thereabout adjacent a surface of said die plate for compressing and forcing material through the perforations thereof, means for rotating said sleeve, and means disposed adjacent one end of said shaft and sleeve for preventing relative axial movement therebetween.

17. In apparatus of the class described, a perforated die plate, a column secured at one end to said die plate, a sleeve disposed about said column, means supported by said sleeve and adjacent one face of said die plate for compressing and forcing material through the perforations therein, a housing enclosing one end of said column and the adjacent end of said sleeve, a thrust bearing disposed in said housing between the ends of said column and said sleeve, and means for rotating said sleeve.

18. In apparatus of the class described, a perforated die plate, a columnsecured at one end to said die plate, a sleeve disposed about said col' umn, means supported by said sleeve and adjacent one face of said die plate for compressing and forcing material through the perforations any) therein, a housing enclosing one end of said column and the adjacent end of said sleeve, a thrust bearing disposed in said housing between the ends of said column and said sleeve, a prime mover,-

and means within the housing for connecting said prime mover with said sleeve to effect rotation thereof.

19. In apparatus of the class described, a housing. a chamber in said housing having an aperture opening into said housing, a perforated die plate mounted in said housing, a column secured to said die plate and extending through said aperture, a sleeve disposed about said column and extending through said aperture, means mounted on said sleeve and adjacent one face of said die plate for compressing and forcing material through the perforations therein, means for rotating said sleeve, and means disposed within said chamber and adjacent the ends of said column and sleeve for transmitting thrust stresses therebetween.

20. In apparatus of the class described, a housing, a rotatable upright member mounted in said housing, a horizontally positioned apertured die plate, means for supporting said die plate so constructed and arranged as not to overlie the apertured portion of said die plate, a roller mounted for orbital movement about said upright member and adapted to extrude material through said die apertures, a ring positioned substantially at the surface of said die plate and without the discharge path of the extruded material, a knife carried by said ring and movable therewith for severing the extruded material, and means outside the discharge path of the material for rotating said ring.

EDGAR T. MEAKIN. 

